[Xen-changelog] [xen-3.4-testing] x86 shadow: don't try to unsshadow for p2m changes after the shadows

["Xen patchbot-3.4-testing" <patchbot-3.4-testing@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1259310859 0
# Node ID e89ccff41980090abb71181ec4e12d9b873da185
# Parent  7c0c26abbf2824fcf5f4096f011b1c24409ac21a
x86 shadow: don't try to unsshadow for p2m changes after the shadows
have been torn down.

Signed-off-by: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
xen-unstable changeset:   20508:e6515469c466
xen-unstable date:        Thu Nov 26 11:31:16 2009 +0000
---
 xen/arch/x86/mm/shadow/common.c |   25 +++++++++++++++++++------
 1 files changed, 19 insertions(+), 6 deletions(-)

diff -r 7c0c26abbf28 -r e89ccff41980 xen/arch/x86/mm/shadow/common.c
--- a/xen/arch/x86/mm/shadow/common.c   Fri Nov 27 08:33:48 2009 +0000
+++ b/xen/arch/x86/mm/shadow/common.c   Fri Nov 27 08:34:19 2009 +0000
@@ -3417,14 +3417,12 @@ static int shadow_test_disable(struct do
  * with new content. It is responsible for update the entry, as well as other 
  * shadow processing jobs.
  */
-void
-shadow_write_p2m_entry(struct vcpu *v, unsigned long gfn, 
-                       l1_pgentry_t *p, mfn_t table_mfn, 
-                       l1_pgentry_t new, unsigned int level)
+
+static void sh_unshadow_for_p2m_change(struct vcpu *v, unsigned long gfn, 
+                                       l1_pgentry_t *p, mfn_t table_mfn, 
+                                       l1_pgentry_t new, unsigned int level)
 {
     struct domain *d = v->domain;
-    
-    shadow_lock(d);
 
     /* If we're removing an MFN from the p2m, remove it from the shadows too */
     if ( level == 1 )
@@ -3480,6 +3478,21 @@ shadow_write_p2m_entry(struct vcpu *v, u
                 unmap_domain_page(npte);
         }
     }
+}
+
+void
+shadow_write_p2m_entry(struct vcpu *v, unsigned long gfn, 
+                       l1_pgentry_t *p, mfn_t table_mfn, 
+                       l1_pgentry_t new, unsigned int level)
+{
+    struct domain *d = v->domain;
+    
+    shadow_lock(d);
+
+    /* If there are any shadows, update them.  But if shadow_teardown()
+     * has already been called then it's not safe to try. */ 
+    if ( likely(d->arch.paging.shadow.total_pages != 0) )
+         sh_unshadow_for_p2m_change(v, gfn, p, table_mfn, new, level);
 
     /* Update the entry with new content */
     safe_write_pte(p, new);

_______________________________________________
Xen-changelog mailing list
Xen-changelog@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-changelog